H.sub.2 O.sub.2 is a weakly acidic, clear, colorless liquid miscible in all proportions with water. It is widely used in bleaching operations, in the preparation of other peroxygen compounds, and as an oxidizing agent.
Most H.sub.2 O.sub.2 is currently made using a process involving an anthraquinone compound as the hydrogen carrier. This process was first operated in Germany during World War II. In the process, an alkyl-anthraquinone such as a 2-alkyl-anthraquinone is dissolved in a in a solvent system such as a mixture of benzene and C.sub.7 -C.sub.9 alcohols, trialkylphosphates, tetraalkyl-substituted ureas, dialkylcarboxylic acid amides, 1,3,5-tritetraalkylazene, 2,6-dialkylcyclohexane, pivalic esters, mono- and diacetylbenzoquinone, and diacetylbenzene. The dissolved anthraquinone or "working solution" is mixed with with hydrogen and a hydrogenation catalyst such as palladium-black, Raney nickel, or nickel boride. The anthraquinone is reduced to the corresponding anthraquinol (or anthrahydroquinone). The working solution is separated from the catalyst and contacted with air to again produce the anthraquinone. Simultaneously H.sub.2 O.sub.2 is formed and is then extracted with H.sub.2 O to form an H.sub.2 O.sub.2 solution. The H.sub.2 O.sub.2 solution is purified and concentrated if needed. The working solution is recycled.
This process suffers form a wide variety of maladies. Many involve secondary "over-reduction" reactions or degradation reactions of the anthraquinone during the process cycle. The solvents are often degraded through oxidation. Many of the resulting byproducts end up in the aqueous H.sub.2 O.sub.2 solution and must be subsequently removed thereby adding to the cost of the process.
The inventive process does not involve the use of anthraquinone but instead uses fullerenes as the hydrogen carrier.